Having spent as much money and energy as I can rationalize, I try to run my Pershing and Sherman every week at least. I live in Phoenix and have run them on grass and hard packed dirt quite often with no ill effects. The dust and oxidation from the sun light seem to be weathering my tanks quite nicely. I try not to fire the main guns excessively in order to preserve the life of the flash unit; I entertain observers with the machine gun mostly. Sooner or later I will find a good battle and really wring my machines out. I have to learn not to worry about dinging up the details I have added as I run the tanks.